Tuning the 6 speed transmissions is a lot more involved than the 4l60e but when done right the transmission hold up very well. You cannot simply delete the torque management and add some line pressure with these as they will be finicky and have odd problems like are described in the thread.

That being said the mph tables are VERY important on these transmissions. If there is any fluctuations between the tables the transmission will not shift correctly at wot. Also you cannot use the same tune in these transmissions. Every one acts a bit different. Some transmissions shift very good with just some torque management taken out. Some need 20-35 psi more line pressure to shift the same way. Almost all the bottle tunes I have done need some pressure added especially on the 3-4 shift as 4th gear is the weakest in the 6ls

Most of the problems mentioned earlier can be eliminated in the tune, however the person who complained about the 2-3 occasional flair, this is a common problem after torque management has been cut down more the. 50% or disabled. It almost always happens after the vehicle has been sitting whether its cold or hot. The reason is the 2-3 piston does not hold fluid well so when it is commanded to shift into 3rd it has no fluid present and has a flare. By the time the next shift Is commanded the fluid is there and it shifts just fine after that.

 

Thankyou very much for sharing that info . Good stuff

 

This. Lots of people just kill all TQMGT and wonder why it act's like ****.

 

the biggest killer i see of them is people removing all of the torque management. not good kids. clutch to clutch trans needs a bit of it in there to live happy.

every 6l80's i have tuned were from 280hp to the tire up to 700whp. all in stock trim and all of them still happy to this day. the tune is the major key to them living.

 

I'm a 6l80e fan due to the gearing. Although I've probably had the worst luck with some things it seems to be doing great now.
To start I blew my 4l70e back in 2011 and did the 6l80e swap. The tranny had around 40k miles on it when I put it in. From there it lasted about 7 months & 15k miles before I broke it... And when I say broke it i mean destroyed it!
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So from there I ordered PATC 6l80e 1200hp kit, had it installed and I put it all back together. It took about a week to get all the tuning corks worked out with converter lockup and stuff but felt Ok. I was expecting it to shift harder due to the wave plate removal & higher pressures (the kit has powergluide clutch packs now). It just seemed to shift like a normal tranny which should have gave me some indication that something was wrong! It lasted 3 more weeks and I burned the 3-5-R clutch pack. So I took it back apart looking for a cracked 3-5-R drum but it wasn't. So at this time I called up PATC and they said it's a possible valve body failure and I could have it remed or purchase a new one. I was getting cross bleeding from metal erosion. So I bought a new one and put everything back together & now it a BEAST! Shifts hard like a 4l80e with a kit! It has been holding up for a few months now and that's saying alot considering I 4wd launch this truck very often and stay @ WOT all the time! Truck weighs 6,020lbs in race trim and went 12.90's on motor. I pull my 5th wheel camper once every 2 months or so and it does great. I go off road every chance I get and roll on 35's daily.

I think with the right tuning these trannys are a very good transmission. I had a run off bad luck on some parts that were causing failure. Good to go now!

Things I learned during this process = 2009 1/2 and later 6l80e have some revision in the transmission such as the seal/oring set up on the 3-5-R drum has tabs on it to keep it from spinning and causing premature wear. Also the 2011+ 6l80e have a better pump & seal design to prevent flare between gears.

 

Wheel hop will kill the rear planetary with power or weight. There is a billet planetary available.

 

Who makes the billet planet?

 

Nah my ’11 5.3 2WD never took off from stationary in anything but 1st (4.027:1).

It’s an entirely different truck after Justin tweaked tip-in abuse, PT and WOT speed/rpm, downshift sensitivity, PWM lock-up delay and slip, and line pressure(s).

Shift timing/speed/firmness is now perfect for my workaday needs, but only after asking for “firmer!” a couple of times during the ride-along tuning process.
He reduced TM primarily on the engine side (timing & TB) and left much in the TCU for longevity.

Only ~32,000 trouble-free miles to date. Never a hiccup along the way.
When it breaks I’ll just bolt in a new one. :)

 

That good you have info on the PATC kits I was really interested in them also with Century's 6l80 builds. Think eventually I'm gonna send my trans to them and see what can be done. They say they do the same mods as PATC. So as far as shift firmness and shift speed, how do you like it?

 

the rule of mph must match rpm doesn't qualify with the 6l80's. it uses the mph as a stage 1 trigger then rpm as the final trigger point.